Wheel chair with extensible wheel base to facilitate ingress and egress

ABSTRACT

According to the invention, there is provided a wheelchair having a propelling wheel, the said wheel being held in a wheel holder which in turn is mounted both pivotally and slidingly from a first forward position to a second backward position with respect to the seat and backrest of the wheelchair, a lock means being provided which is adapted to lock the said wheel holder in either of the said extreme positions.

United States Patent Danziger et al.

[ 1 Aug. 26, 1975 WHEEL CHAIR WITH EXTENSIBLE WHEEL BASE TO FACILITATEINGRESS AND EGRESS Inventors: Uzi Danziger; Reuven Danziger, both of 13Brener St., Netanya, Israel Filed: Mar. 8, 1974 Appl. No.1 449,481

Foreign Application Priority Data Mar. 8, 1973 Israel 41737 US. Cl.280/34 R; 280/21 1; 280/242 WC; 297/417 Int. Cl. A16G 5/00 Field ofSearch 280/242 WC, 242 R, 21 1, 280/289, 34 C; 297/417, DIG. 4, DIG. 1O

[56] References Cited UNITED STATES PATENTS 3,185,495 5/:1965 Pivacek280/34 3,618,968 11/1971 Greer 280/47.11

Primary Exam inep-Leo Friaglia Attorney, Agent, or FirmBrowdy andNeimark [57] ABSTRACT According to the invention, there is provided awheelchair having a propelling wheel, the said wheel being held in awheel holder which in turn is mounted both pivotally and slidingly froma first forward position to a second backward position with respect tothe seat and backrest of the wheelchair, a lock means being providedwhich is adapted to lock the said wheel holder in either of the saidextreme positions.

4 Claims, 7 Drawing Figures WHEEL CHAIR WITH EXTENSIBLE WHEEL BASE TOFACILITATE INGRESS AND EGRESS BACKGROUND OF INVENTION The presentinvention relates to a wheelchair, in particular to a wheelchair havingtwo rear propelling wheels and either two detachable or folding armrestsor only one such armrest, while the second remains fixed.

The invention is especially, but not exclusively, useful with respect towheelchair constructions for the kind of user who is capable ofpropelling the said wheelchair manually by rotating the wheels with hishands but has great difficulty in transferring himself to another chair,car or bed, and due to the weakness of limbs is unable to stand up orsufficiently raise his torso.

The advantage of such manually operated wheelchairs resides in itsallowing the user a maximum of independent mobility, as can be expectedunder such circumstances.

The disadvantage of such manually operated wheelchairs for said kind ofuser is that due to the fact that the propelling wheel does not permitthe user to slide across the wheelchair, which prevents the user of thechair from moving in a lateral direction.

The object of the present invention is to provide a manually operatedwheelchair which is designed to overcome the aforementioned problem.

SUMMARY OF INVENTION In the following description the said firstposition will be referred to as transporting position, since in thatposition the wheelchair can be used to transport its rider from oneplace to another. The said second positior: will be referred to as.transferring position, since in it, the rider can transfer himself fromthe wheelchair to another means of support, say another chair, the bedor the like.

In a practical embodiment of the invention, the holder comprises anarcuate guide which is pivotally attached to the rear of the chassis ofthe wheelchair and which is slidingly displaceable in relation to thesaid chassis, the said propelling wheel being rotatably attached to thewheel holder and an operating pullingpushing handle being provided formoving the wheel holder and the propelling wheel between said extremepositions. i I

According to a further feature of the invention,.the said lock iscomprised of a hinge pivotally connecting the lock to the wheelchairbody, a latch locking said wheel holder in either of its extremepositions, and an operation release handle for releasing said wheelholder from the catch of the latch.

Since the novel wheelchair is opened in its transferring position on theseat side by locating the propelling wheel at the rear of the seat, itis possible to provide a convertible armrest which istransformed into asliding ing it at its armresting position.

This part of the invention makes unnecessary the use of a specialadditional sliding board separate from the wheelchair, and is intendedfor use by the invalid rider of the wheelchair, enabling that person toslide from the chair ontoanother support.

Further features and advantages of the invention will be apparent fromthe description below.

SHO T DESCRIPTION OF DRAWINGS in a position intermediate the two extremepositions.

FIG. 3 is another elev-ational view illustrating the wheel in thebackward lockedtransferring position, and the construction of theconvertible armrest.

FIG. 4 is a fractional perspective view illustrating the constructionand operation of the wheel locating arrangement while it is in themidposition.

FIG. 5 is a partial perspective view illustrating the wheelchair in itstransferring position, with the wheel locked in its backward locationand the armrest converted to its horizontal sliding position.

FIG. 6 is a fractional perspective view illustrating the construction ofthe armrest pivoting and mounting arrangement.

FIG. 7 is a perspective view illustrating the embodiment of wheelchairin which both rear wheels and both armrests are pivotable.

DESCRIPTION OF PREFERRED EMBODIMENT The wheel holder designated as awhole by the numeral l is comprised of a tubular member 2 (see FIG. 4),a fork 3 carried by the tubular member 2 and connected to it as bywelding, having drilled holes, 4 at its lower end. At its upper end thetubular member 2 carries a hollow cross piece 5, as by welding. Crosspiece 5 carries on its inner end i.e., that side which faces thewheelchair, e.g. by having welded to it, an arcuate guide rail 6 shapedof flat metal and being curved with holes 4 as centre, handle 7 isaffixed to cross piece 5, e.g. being welded to it, on its upper side.The handle 7. includes a padded grip 8 on its upper end (see FIGS. 1 and2). An ear or bracket 14 is carried on the rearwardly extending bar 15,forming part of the chassis being affixed by shackles l7. The fork 3rides on the bar 15, a pin 16 passes through holes 4 and the bracket 14.The arcuate guide 6 is slidingly connected to the chassis bymeans of abolt 18 which passes through a spigot 19 extending from the chassis. Theguide 6 is positioned on the inner side with respect to the wheelchairbody.

Said wheel holder 1 is mounted swingingly on the wheelchair body, andtherefore by pushing and pulling said handle 7, the wheel holder 1 movesabout its centre 4, its arcuate guide 6 sliding on body pivot 19 alongits arcuate slot 9 between the closed ends 10 and II of the slot 9, itsmovement being limited by the bolt 18. The propelling wheel 20 beingcarried on the cross piece 5 by a pin 22 which passes also through thewheel hub 21, can be moved backward and forward between its two extremepositions carried by the wheel holder 1.

For the purpose of locking the wheel in either of its said extremepositions a wheel lock is provided.-

The wheel lock 23 comprises a pawl 24 connected by a curved arm 24 to aneye 25. From arm 24' extends releasing handle 26.

The handle bar 26 has a padded grip 27 on its free end. The lock 23 ismounted pivotally by means of the eye on the spigot 19 opposite thearcuate guide and is joined together with the guide 6 by the bolt 18.

While the propelling wheel 20 is in its forward transporting position,pawl 24 is engaged in an appropriate catch 12 on the rear part of thearcuate guide 6 holding the wheel 20 in said position. Respectively,when wheel 20 is in its backward transferring position, pawl 24 engagesover the front end 13 of the arcuate guide 6.

As can be learned from FIGS. 1 and 3, while the propelling wheel 20 isin either of its extreme positions, the wheel holder member 2 isinclined about in a forward direction or a backward direction relativeto the vertical. Therefore when releasing handle 26 is lifted fromeither engaged position, member 2 assumes a vertical position due to theforce generated by the weight of the wheelchair body and the user. Whilemember 2 is in the vertical position, wheel 20 is in the midway positionbetween its two extremes. On the other hand, when the wheel locatinghandle 7 is either pushed or pulled from its midway position toward oneof its extreme positions, the locking pawl 24 is engaged by theappropriate catch, either 12 or 13, by the force of the weight of thereleasing handle 26 as suggested in FIGS. 1, 2 and 3.

These two features of the invention discussed above, i.e., thegravitationally self changing propelling wheel being moved to the halfway position by only lifting the releasing handle 26, and thegravitationally self locking of the latch 24 being achieved by onlypulling or pushing the wheel locating handle 7 to desired position,simplify the construction of the wheelchair according .to the inventionwithout special need for springs or other problematic mechanisms, andwhich is even more important these features enable the user to operatethe wheel location by two simple movements of one hand, as describedabove.

The convertible armrest indicated as a whole by the numeral 30 comprisesa tubular bent frame 31 carrying on its inwardly facing side, (inrespect to the seat 28), a plane surfaced rigid sheet 32, of metal orhard plastic. The frame 31 is provided at its lower corners 33 and 34with two hinge members 36 and 37 of any known kind co-operating with twocorresponding hinge members 38 and 39 provided on two tubular members 40and 41, which are mounted adjustably and detachably by means of twobolts 42 and 43 in two sleeves and 46 carried on the wheelchair bodye.g. being welded thereto. A spring operated lock positioned on thechassis, in register with point 43 secures the rear upper corner of thearmrest 30 in its vertical armresting position.

The members 40 and 41 have a plurality of adjustment holes 44 (see FIG.7) and the sleeves 45 and 46 have, respectively, one corresponding hole47 and 48. While armrest 30 is in its horizontal sliding position, thesliding surface 32 has to be on the same level with the sitting planewhich is not always identical with the wheelchair seat surface 28,because some users employ seat cushions to prevent decubitus ulcers. Theplurality of holes 44 enables the selection of the appropriate surfacelevel of the armrest sheet 32.

The mode of operation of the novel wheelchair will be apparent from thefollowing description.

Transfer of wheelchair rider to another (stationary) seat The wheelchairis in transporting position occupied by the user preparing to transferhimself to another seat. The wheelchair is brought near the desiredstationary seat. The user, or his assistant, lifts the releasing handle26 whereupon the propelling wheel 20 drops to the midposition, theoperator then pushes back the wheelplacing handle 7 until the releasinghandle 26 falls into its lower position signifying that the pawl 24 isin engaging position i.e., the wheel 20 is locked in its backwardposition behind seat 28 and backrest 29. Then the operator releases thearmrest 30 from its vertical closed position, the operator pivots thearmrest 30 to the horizontal position until it rests on the edge of thedesired seat. The wheelchair is then prepared for transferring.

Transfer from a stationary seat onto the wheelchair The wheelchair isunoccupied and a user is preparing to transfer himself onto thewheelchair. The wheelchair is brought to transferring position in thesame way as described above and, after the transferring operation iscompleted, the operator pivots the armrest 30 to its vertical positionuntil the armrest 30 is engaged by the lock '50. Then the operator liftsthe releasing handle 26, the propelling wheel 20 drops to itsmidposition, wheel locating handle 7 is pulled forward by the operatoruntil the releasing handle 26 drops to its lower position signifyingthat the pawl 24 is engaged i.e. the wheel 20 is locked in its forwardposition, and the wheelchair is ready in its transporting position.

It will be appreciated that the above described construction could beused in part only, for example, without the convertible armrest but witha conventional detachable armrest, or with a convertible armrestprovided to fit a so-called car transit chair, i.e., a wheelchair havingsmall wheels only, and intended for operation by an assistant. It willalso be appreciated that characteristic parts of the above describedinvention could be mounted on a conventional wheelchair even by theconsumer, since these parts could be prepared for fitting thosewheelchairs, without disturbing their positive properties, e.g. theircollapsibility or stability. These aforementioned variant applicationsmay be made within the scope of the invention as defined in thefollowing claims.

Many other changes, variations and applications of the illustratedembodiment may be made within the scope of the invention, as defined inthe following claims.

What is claimed is:

l. A wheelchair comprising:

a chassis;

a seat for a rider, mounted on said chassis;

first and second rear propelling wheels disposed on opposite sides ofsaid chassis;

a wheel hub, having mounted thereon one of said rear propelling wheels;

a pivot arm pivotably connecting said wheel hub to said chassis at afixed pivot point thereon;

an arcuate guide connected to said wheel hub and slideably engaging saidchassis at a point on said chassis above said pivot point, said arcuateguide defining an arcuate path of said wheel hub about said pivot pointbetween two opposite end positions of said arcuate guide;

said pivot point being positioned on said chassis at a pointsubstantially vertically below a midpoint along said arcuate pathbetween the two opposite end positions; and

hub locking means for locking said wheel hub in either of the two endpositions of the arcuate path.

2. A wheel chair according to claim 1, further including:

a second wheel hub having mounted thereon the other of said rearpropelling wheels;

a second pivot axis pivotably connecting said second wheel hub to saidchassis at a second fixed pivot point thereon;

a second arcuate guide connected to said second wheel hub and slideablyengaging said chassis at a point on said chassis above said second pivotpoint, said second arcuate guide defining an arcuate path of said secondwheel hub about said second pivot point between two opposite endpositions of said second arcuate guide;

said second pivot point being positioned on said chassis at a pointsubstantially vertically below a midpoint along said arcuate path ofsaid second wheel hub between the two opposite end positions; and

second means for locking said second wheel hub in either of the two endpositions of the arcuate path thereof.

3. A wheelchair according to claim 1, further including:

first and second armrests attached to opposite sides of said chassis;

a rigid plane surface disposed on one of said armrests on the sidethereof facing said seat. said one of said armrests being hinged to saidchassis to be swingable from a vertical position to a horizontalposition; and

armrest locking means being provided for securing said armrest in eitherthe vertical or horizontal position thereof;

said pivot point being disposed and said pivot arm and said arcuateguide being of such size that when said wheel hub is in one of the endpositions of the arcuate path, said armrest is swingable into thehorizontal position thereof in a plane below the uppermost verticalextention of said one of said rear propelling wheels without contactingsaid one of said rear propelling wheels.

4. A wheelchair according to claim 2, further including:

first and second armrests attached to opposite sides of said chassis;

first and second rigid plane surfaces disposed on respective ones ofsaid armrests on the sides thereof facing said seat, each of saidarmrests being hinged to said chassis to be swingable from a verticalposition to a horizontal position; and

first and second armrest locking means being provided for securingrespective ones of said armrests in either the vertical or horizontalpositions thereof;

said pivot points being so disposed and said pivot arms and said arcuateguides being of such size that when respective ones of said wheel hubsare in one of the end positions of the respective arcuate paths, therespective ones of said armrests are swingable into the horizontalpositions thereof in planes below the uppermost vertical extensions ofthe respective ones of said rear propelling wheels, without contactingthe respective ones of said rear propelling wheels.

1. A wheelchair comprising: a chassis; a seat for a rider, mounted onsaid chassis; first and second rear propelling wheels disposed onopposite sides of said chassis; a wheel hub, having mounted thereon oneof said rear propelling wheels; a pivot arm pivotably connecting saidwheel hub to said chassis at a fixed pivot point thereon; an arcuateguide connected to said wheel hub and slideably engaging said chassis ata point on said chassis above said pivot point, said arcuate guidedefining an arcuate path of said wheel hub about said pivot pointbetween two opposite end positions of said arcuate guide; said pivotpoint being positioned on said chassis at a point substantiallyvertically below a midpoint along said arcuate path between the twoopposite end positions; and hub locking means for locking said wheel hubin either of the two end positions of the arcuate path.
 2. A wheel chairaccording to claim 1, further including: a second wheel hub havingmounted thereon the other of said rear propelling wheels; a second pivotaxis pivotably connecting said second wheel hub to said chassis at asecond fixed pivot point thereon; a second arcuate guide connected tosaid second wheel hub and slideably engaging said chassis at a point onsaid chassis above said second pivot point, said second arcuate guidedefining an arcuate path of said second wheel hub about said secondpivot point between two opposite end positions of said second arcuateguide; said second pivot point being positioned on said chassis at apoint substantially vertically below a midpoint along said arcuate pathof said second wheel hub between the two opposite end positions; andsecond means for locking said second wheel hub in either of the two endpositions of the arcuate path thereof.
 3. A wheelchair according toclaim 1, further including: first and second armrests attached toopposite sides of said chassis; a rigid plane surface disposed on one ofsaid armrests on the side thereof facing said seat, said one of saidarmrests being hinged to said chassis to be swingable from a verticalposition to a horizontal position; and armrest locking means beingprovided for securing said armrest in either the vertical or horizontalposition thereof; said pivot point being disposed and said pivot arm andsaid arcuate guide being of such size that when said wheel hub is in oneof the end positions of the arcuate path, said armrest is swingable intothe horizontal position thereof in a plane below the uppermost verticalextention of said one of said rear propelling wheels without contactingsaid one of said rear propelling wheels.
 4. A wheelchair according toclaim 2, further including: first and second armrests attached toopposite sides of said chassis; first and second rigid plane surfacesdisposed on respective ones of said armrests on the sides thereof facingsaid seat, each of said armrests being hinged to said chassis to beswingable from a vertical position to a horizontal position; and firstand second armrest locking means being provided for securing respectiveones of said armrests in either the vertical or horizontal positionsthereof; said pivot points being so disposed and said pivot arms andsaid arcuate guides being of such size that when respective ones of saidwheel hubs are in one of the end positions of the respective arcuatepaths, the respective ones of said armrests are swingable into thehorizontal positions thereof in planes below the uppermost verticalextensions of the respective ones of said rear propelling wheels,without contacting the respective ones of said rear propelling wheels.